Stuck in the mud: Spring restoration to improve fish habitat in the Conasauga River drainage

Colvard Spring, in the Conasauga River drainage in Whitfield County, GA, is home to the imperiled coldwater darter (Etheostoma ditrema).  Logging immediately adjacent to Colvard Spring during the 1980s resulted in deposition of deep (to 1m) deposits of silt, with anecdotal reductions in darter abundance.  We undertook a joint project to remove this sediment to increase habitat for coldwater darters.  For one year prior to treatment, we monitored habitat availability and the population size of coldwater darters in Colvard Spring and a nearby control spring, Cohutta Spring.  An estimated 408 individuals (95% CI of 357-459) occupied Colvard Spring prior to treatment, compared with 262 individuals (95% CI of 247-277) in the smaller Cohutta Spring.  Sediment removal was conducted in October 2009 using an 8 cm trash pump to entrain and pipe the sediment slurry into a section of neighboring field surrounded by straw erosion control structures.  All fishes and brownback salamanders (Eurycea sp. cf  aquatica) collected in a three-pass depletion survey were moved to a hatchery facility for the duration of the sediment removal process and were returned in November 2009.  We continue to monitor both springs to determine the response of aquatic vegetation, darters and salamanders to treatment.